Zim Wiki - Zim is a graphical text editor used to maintain a collection of wiki pages. Each page can contain links to other pages, simple formatting and images.
DokuWiki - DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
TiddlyWiki - a non-linear personal web notebook
VoodooPad - VoodooPad is a personal wiki developed for the Mac OS. It lets users create a personal wiki by giving them the ability to manage a network of pages right from the desktop.
Pepperminty Wiki - An entire wiki in a single PHP file. Intended for small - medium sized wikis.
MarkWiki - MarkWiki is a wiki that uses Markdown to create pages